An integrated circuit card with an interface terminal strip strip and a method of manufacturing such a card
The invention relates to an integrated circuit card with an interface terminal strip between the integrated circuit and contact areas produced by the deposition of ink.
The invention relates more particularly to an integrated circuit card of the type having a card body in which there is arranged at least one integrated circuit electrically connected to contact areas on which contact blades of an operating circuit are intended to bear, and of the type in which the contact areas are formed by the deposition of a conductive ink.
In standard integrated circuit cards, an international standard defines notably the number, size and position of the contact areas with respect to the external edges of the card body so that a card in accordance with the standard can be used in a large number of types of apparatus having an operating circuit intended to exchange information with the integrated circuit contained in the card. Each of these items of equipment has for example a connector provided with a series of contact blades which are intended to come into abutment against the contact areas of a card engaged in the connector, the contact blades providing the electrical connection between the integrated circuit of the card and the operating circuit of the equipment.
According to the standard, the size of the contact areas is relatively large in order to guarantee with certainty that the blades of the connector come into contact on the areas on the card, without imposing excessively strict constraints with regard to the relative positioning of the card and connector.
In very many integrated circuit cards, the contact areas are produced by cutting a metallic plate, possibly coated with one or more precious metals intended to improve the quality of the electrical contact.
For the purpose of reducing the cost of integrated circuit cards, it has already been proposed to reduce the costs related to the cost of the material constituting the contacts. It has notably been proposed to produce integrated circuit cards whose contact areas are produced by the deposition of a conductive ink, for example by screen-printing, offset, flexographic printing, pad printing or any derived technology.
Thus integrated circuit cards are known in which the integrated circuit is directly implanted in the card body, one of its faces lying flush at the level of the top face of the card body, and in which both the contact areas and the connection means between the integrated circuit and the contact areas are produced by various screen-printing operations.
A first drawback of this technology is that the implantation of the integrated circuit in the card body must be effected with a great deal of precautions in order not to break it since it has no protection at that time. In addition the implantation of the integrated circuit must be effected with great precision, notably angular precision. This is because an angular error of 6 degrees on the chip will create a lack of parallelism of 1 mm on the contact areas. Another drawback is that the screen-printing operations which form the contact areas and connect them to the terminals of the integrated circuit are particularly tricky, notably with regard to the relative positioning of the integrated circuit and the contact areas. To ensure sufficient reliability of this operation, it is often necessary to use computer-aided artificial vision systems, in order to obtain a sufficiently precise positioning. However, the precision required for this screen-printing operation prevents it being carried out at a high rate, which extends the time taken for manufacturing the card and therefore its cost.
The object of the invention is therefore to propose a novel design of an integrated circuit card, and a novel method of manufacturing an integrated circuit card which make it possible both to significantly reduce the cost of the raw material for the card, whilst increasing the possibility of using very high production rates which alone make it possible to obtain low cost prices for such a card.
For this purpose, the invention proposes an integrated circuit card of the type described above, characterised in that the card has an interface terminal strip provided with a series of terminals electrically connected to terminals on the integrated circuit, and in that the contact areas are formed on the top face of the card body so that each area has a portion which covers (or contacts) at least partly a terminal on the interface terminal strip so as to electrically connect the said contact area to the said terminal on the terminal strip.
Thus a technique for the economical production of contact areas (by the deposition of conductive ink) is combined with the use of a smaller module on which the chip has its pads connected to terminals of sufficiently large size to allow easy connection with the contact areas by means of a deposition of ink.
The invention also has the advantage of increasing the yield in obtaining modules from the same support strip.
According to other characteristics of the invention:
the interface terminal strip is formed by cutting a plate element made of conductive material;
the interface terminal strip is formed by cutting a plate element made from metallic material;
the terminal strip and the integrated circuit are assembled in order to form a module received in a recess provided in the card body; and
the integrated circuit is fixed to a bottom face of the terminal strip.
Another object of the invention is to propose a method of manufacturing an integrated-circuit card, characterised in that it includes the steps consisting in:
cutting an interface terminal strip from a plate element made of conductive material;
electrically connecting corresponding terminals of the integrated circuit and terminal strip;
arranging the terminal strip and the integrated circuit in a card body so that a top face of the terminal strip lies flush with the level of a top face of the card body;
producing contact areas by the deposition of a conductive ink on the top face of the card body so that each area has a portion which at least partly covers a terminal on the interface terminal strip so as to electrically connect the said contact area to the said terminal on the terminal strip.
According to yet other characteristics of the invention:
the method includes the step consisting in producing a module including the integrated circuit and the terminal strip, and the module is subsequently inserted in a recess provided in the card body;
the method includes the step consisting in producing a module including the integrated circuit and the terminal strip and, subsequently, the card body is moulded on around the module;
the step of producing the module includes the step consisting in cutting, in a plate element, slots demarcating the terminals on the terminal strip, the said terminals each remaining connected to an external contour of the plate element;
the step of producing the module includes the step consisting in fixing the integrated circuit to a bottom face of the terminal strip;
the step of producing the module includes the step consisting in applying, to the bottom face of the terminal strip, a layer of support resin;
the step of producing the module includes the step consisting in separating the module from the plate element by separating each of the terminals on the terminal strip from the contour of the plate element; and
the plate element is a strip along which a series of modules are produced.